The Collaborative International Dictionary of English v.0.48:

Umbellularia \Um*bel`lu*la"ri*a\, prop. n. [NL. See
   Umbellule.] (Zool.)
   A genus of deep-sea alcyonaria consisting of a cluster of
   large flowerlike polyps situated at the summit of a long,
   slender stem which stands upright in the mud, supported by a
   bulbous base.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Umbellularia
    n 1: aromatic evergreen trees of Pacific coast [syn:
         Umbellularia, genus Umbellularia]